MICROPROPAGATION STUDIES AND ANTIOXIDANT ANALYSIS OF THE ENDANGERED PLANTS OF BULGARIAN YELLOW GENTIAN (Gentiana lutea L.)

Abstract

In order to develop an efficient micropropagation system, it is essential to establish the appropriate concentration of growth regulators for seed germination, shoot formation and rooting. Nodal segments from in vitro obtained seedlings of Gentiana lutea L. were cultured in vitro in Murashige and Skoog’s medium supplemented with BAP, Thidiazuron and Zeatin (0.5, 1.0 and 2.0 mg L⁻¹). A maximum number of shoots with the highest height was recorded at 2.0 mg L⁻¹ BAP. For further optimization of the process, we used nutrient media containing BAP and Zeatin with a combination of low concentration of Indoleacetic acid. MS medium containing 2.0 mg L⁻¹ Zeatin and 0.2 mg L⁻¹ IAA resulted in maximum numbers of shoots 94.3) with shoot height 2.5 cm. The multiple plants were successfully ex vitro acclimatized with 65% survival. The presence of growth regulators (2.0 mg L⁻¹ Zeatin and 0.2 mg L⁻¹ IAA) in the nutrient media resulted in an effective antioxidant activity in G. Lutea determined by the low molecular antioxidant metabolites such as phenols and flavonoids and activities of antioxidant enzymes – catalase, ascorbate peroxidase, guaiacol peroxidase, and superoxide dismutase. The described protocol allows the establishment of numerous micropropaged plants of rare and endangered G. lutea.